DOMAIN V. CALCAREOUS. 



river Marne, and in the rivulet of the Gobelins, 

 as is observed by Lamanon. 



"Infiltrations of black martial earth* often 

 , form very elegant dendrites, on white limestone, 

 mixed with argil. The dissolution of the lime- 

 stone, infiltrating between the clefts of the gyp- 

 sous masses, forms stalagmites composed of un- 

 dulating layers, often distinct by their shades of 

 brown, yellow, and white. These alabasters vie 

 in beauty with the best of this kinds but hitherto 

 they have only been found in thin pieces, often 

 several feet in length. The limestone which in- 

 filtrates into the gypsous masses, is the cause 

 that they almost all effervesce with acids ; ex- 

 cept the plaster-stone with a coarse grain, the 

 crystals of selenite, and those known by the 

 name of gn 'guards, a term bestowed on selenite 

 when it forms regular layers. When these 

 masses are broken with the hammer, they emit 

 a strong odour of decomposed liver of sulphur. 



" The marl forms beds and masses, more or 

 less considerable, in the plaster- quarry of Mont- 

 martre: argil is also found in it in considerable 

 quantity, and in different states: one is tena- 

 cious and ductile; the other exfoliates in drying, 

 and sticks closely to the tongue when tasted. 



* Rather manganese. 



